#include <STC89C5xRC.H>
void dsq()
{
	TMOD=TMOD&0xf0;
	TMOD =TMOD|0x01;
	TF0 = 0;
	TR0 = 1;
	TH0 = 64536 / 256;
	TL0 = 64536 % 256;
	ET0 = 1;
	EA = 1;
	ET0 = 1;
}
void main()
{
	dsq();
	while (1)
	{

	}
}

void qths()  interrupt 1
{
	static unsigned int a = 0;
	TH0 = 64536 / 256;
	TL0 = 64536 % 256;
	a++;
	if (a == 1000)
	{
		a=0;
		P20=~P20;
	
	}
}

